Cyber Monday, the busiest online shopping day of the year, is likely to lure many workers to go online in search of Cyber Monday deals. This year, only a third of companies are blocking access to online shopping sites, according to a recent survey.

In this photo taken earlier this month, the Sierra Trading Post Fulfillment Center sits stocked in preparation for Cyber Monday in Cheyenne, Wyo. Businesses are becoming more lenient this year about allowing workers to shop from work.

Amanda Rice expects to do some of her holiday shopping at work this year.

"A lot," says the third-year PhD student in Boston. "Friday, I bought my brother a Boston Bruins bobble-head doll. It was on sale on eBay."

It may sound as though Ms. Rice is slacking off by buying hockey memorabilia when she's supposed to be doing muscle research at her Boston University biology lab. But increasingly, businesses are starting to see online shopping as a boon to productivity, rather than a drain. As employees return to work on Cyber Monday, the biggest online shopping day of the year, they may well take advantage of the new leniency.

US companies are becoming much more tolerant when it comes to their employees shopping online at work. Last year, 60 percent of companies blocked employee access to online shopping sites, according to a blind survey of 1,400 chief information officers from a wide range of US firms. This year, only 33 percent of them blocked access.

"It's way down from last year," says John Reed, of Robert Half Technology, a technology firm based in Menlo Park, Calif., which conducted the survey. "Companies are allowing a little more freedom, but making sure people aren't abusing [the privilege]."

Why the shift? For one thing, online shopping is becoming the norm, especially during the busy holiday months. Online spending during November and December is expected to increase 12 percent over 2011, to an estimated $96 billion total, according to the National Retail Federation. Last year, more than half of shoppers who had online access at work shopped online during their lunch breaks or after hours, according to the federation.

Employers "are looking at it from a realistic perspective," Mr. Reed says. "Even if we have a policy saying we don't want you to do this, employees will find a way. Let's at least acknowledge it and put some parameters in place."

What's more, he says, businesses are starting to see online shopping, which takes a fraction of the time it takes to go to a store, as a way to improve efficiency. "Because it's a busy time of year, enabling people to do a little shopping on a break allows them to not waste time by going to a mall, finding a parking place, [and] coming back."

"With my staff, if they need to take a break for 10 or 15 minutes online shopping I have no problem with that," says Susan Roche, an applications development manager at Watson Realty's office in Jacksonville, Fla. "I trust their integrity and professionalism."

Much of that shopping may take place Cyber Monday. According to a survey of 600 consumers by online deal website FatWallet, 62 percent of consumers expect to find the best holiday season deals on Cyber Monday

"It's usually pretty quick" to buy online, says Rice, who has never spent more than half an hour shopping at one time. "We have a lot of lag time when you're waiting for experiments to run, and that's usually when I do most of it,"

If you want your online purchases delivered at work, check with your supervisor or the mail room first.